Experimental verification of coherent diffractive imaging by a direct phase retrieval method with an aperture-array filter

Abstract

Recently, we have proposed a coherent diffractive imaging using a noniterative phase retrieval method with the filter of an aperture array. The first (to our knowledge) experimental demonstration of this coherent imaging is presented here, in which a complex-valued object illuminated by a diode laser is reconstructed from the isolated diffraction intensities of the object's wave field, transmitted through an array filter of square apertures by using the phase retrieval method. This imaging method requires only a single measurement of the diffraction intensity and does not need a tight object's support constraint utilized in iterative phase retrieval algorithms or a reference wave used in holographic techniques.

Coherent diffractive imaging beyond the Fresnel approximation using a deterministic phase-retrieval method with an aperture-array filter

“…These results demonstrate the effectiveness of the extension procedure in Subsection 2.B. The maximum lateral resolution of the present system is given by δ l λ∕2 NA≅ 2.58 μm [15], which is about 10 times the resolution of the previous experiment [14] with the same array filter as in the present system. Thus the two-point resolution criterion in the object plane is obtained by twice the value (5.16 μm) of δ l .…”

“…In the experimental condition that requires a rigorous diffraction formula instead of the Fresnel integral, the extension procedure of the deterministic phase-retrieval method using the first RS integral showed good object reconstructions. The experimental results clearly show that the resolution of the system is limited not by the aperture's size of the array filter but by the NA of array filter, and the resolution is about 10 times larger than that in the previous paper [14].…”

“…In a previous paper [14], the proof-of-concept experiment of our method has been demonstrated at optical wavelengths under the Fresnel diffraction approximation. In the application to x-ray or electron microscopy, however, it is to be desired that the intensity in the two-dimensional (2D) diffraction plane for an object is recorded with a high numerical aperture (NA) beyond the Fresnel diffraction approximation for the sake of high spatial resolution in the object reconstruction.…”

Pupil-resizing Fourier ptychography

“…As the most commonly used methods, off-axis and in-line digital holography can retrieve the complex amplitude by using digital hologram and algorithms [1][2][3][4] . However, an indispensable reference wave used in the methods mentioned above requires more optical components and the range of its Fourier spectrum limits the spatial resolution 5 . Recently, some real-time phase retrieval techniques without the reference wave have been proposed on the basis of pinhole array 5,6 , but the array filter needs special design and some priori information is necessary.…”

A Comparative Study on the Interference Microscopy Imaging and Diffraction Microscopy Imaging for Biological Cells

“…But the iterative algorithm could not be avoided. In addition, phase difference detection [13] and multipinhole sampling array [14] also can be used to detect wavefront.…”